The country music star sparked rumors after she made an appearance as a guest mentor on NBC’s The Voice! Contestants got an extra-special treat when she helped coaches Adam Levine, Gwen Stefani, Blake Shelton, and Alicia Keys prepare for this week’s performances — and the singer looked so different that fans couldn’t help but wonder if she went under the knife.

“Holy Botox, what happened to Shania Twain?” one fan tweeted, and other fans gushed over how great the “That Don’t Impress Me Much”singer looks at her age — but it might not all be natural.

The 51-year-old’s face looks a lot fuller and plumper now than it did in her 30s — back in the 1990s when she was the reigning queen of country music. Two leading NYC-based doctors have weighed in with their expert analysis and they exclusively revealed to Life & Style what kind of procedures she could have undergone in order to maintain her youthful appearance.

"Shania's eyebrows have maintained their nice elevated arch, and her forehead looks smooth and natural," NYC dermatologist Dr. Kenneth Mark said, and he credits Botox for her look.

“She appears to have filler under her lower eyelids to maintain her youthful look," NYC-based plastic surgeon Dr. Yoel Shahar observed. "She's also likely had Botox to her crow's feet."

The doctors suggest that Shania had regular Botox and filler injections and also underwent a nonsurgical treatment that uses ultrasound waves to tighten and tone skin.

Either way, the “Still the One” singer looks great at her age — and fans are delighted that they’ll be seeing a lot more of her! She made history as the first-ever fifth coach to join The Voice and she’s gearing up to debut her first single — from her first studio album in more than a decade — at the Stagecoach Festival later this week.